490
FXUS65 KBYZ 161504
AFDBYZ
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BILLINGS MT
904 AM MDT SUN AUG 16 2026
KEY MESSAGES
- ISOLATED AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS EXPECTED
TODAY AND MONDAY.
- A COLD FRONT TUESDAY LOWERS TEMPERATURES INTO THE UPPER
70S/LOWER 80S, AND BRINGS AN INCREASED CHANCE OF
SHOWERS/THUNDERSTORMS.
- WARMER AND MAINLY DRY CONDITIONS LOOK TO RETURN LATER THIS
WEEK.
UPDATE
WEAK DISTURBANCE MOVING ACROSS EASTERN MONTANA PRODUCING SOME
ISOLATED THUNDERSHOWERS IN NORTHERN CUSTER ATTM. THIS ENERGY MAY
HELP TRIGGER SOME STRONGER STORMS ALONG THE EASTERN STATELINE THIS
AFTERNOON. OTHERWISE, FORECAST IN GOOD SHAPE AS ANOTHER ROUND OF
ISOLATED/SCT LATE DAY SHOWERS AND THUNDERSTORMS EXPECTED IN THE
WESTERN ZONES. BT
DISCUSSION
TODAY THROUGH SATURDAY...
SHOWERS AND STORMS FROM THIS EVENING WILL CONTINUE TO DIE OFF
OVERNIGHT AS THE SHORTWAVE PUSHES THROUGH THE REGION. THIS WILL
MEAN THAT THE FIRST PART OF SUNDAY WILL BE DRY FOR NEARLY THE
ENTIRE FORECAST AREA. WHAT IS A POSSIBILITY FOR MANY AREAS THOUGH
IS FOG. WITH WIDESPREAD DEWPOINTS IN THE 50S DUE TO THE EASTERLY
WINDS, THERE IS PLENTY OF MOISTURE PRESENT AND THERE IS LIKELY
EVEN HIGHER VALUES IN LOCALIZED AREA THAT SAW PRECIPITATION THIS
EVENING.
LIGHT EASTERLY WINDS WILL AID IN UPSLOPE FLOW ACROSS THE REGION
WITH EVEN FURTHER ENHANCEMENT ALONG THE EAST FACING MOUNTAIN
SLOPES. AS WE GET INTO AN AREA OF BROAD SUBSIDENCE BEHIND THE
AFOREMENTIONED SHORTWAVE, MOST OF THE CLOUDS SHOULD CLEAR OUT. IF
THIS DOES END UP BEING THE SCENARIO, THEN WIDESPREAD FOG IS
ANTICIPATED. LOCALLY DENSE FOG IS POSSIBLE AS WELL, ESPECIALLY IN
RIVER VALLEYS, AREAS OF RECENT RAINFALL, AND LOCATIONS NEAR THE
EAST SLOPES OF MOUNTAINS. CONFIDENCE IS FURTHER INCREASED IN THIS
SCENARIO PLAYING OUT AS THE SAME REGIME / INGREDIENTS WERE
PRESENT SATURDAY MORNING WHEN LOCALLY DENSE FOG WAS OBSERVED IN
SEVERAL LOCATIONS.
LATER IN THE DAY TODAY THERE WILL BE ANOTHER VORT MAX THAT MOVES
THROUGH MONTANA AIDED BY A WEAKLY DIGGING TROUGH OVER THE CANADIAN
ROCKIES. THIS FEATURE WILL BRING YET ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS AS IT QUICKLY PUSHES THROUGH THE REGION. THERE IS
POTENTIAL FOR A STRONG TO ISOLATED SEVERE STORM IN FAR SE MONTANA
EARLY SUNDAY EVENING AS THE AREA OF LIFT MOVES INTO A REGION WITH
MODEST CAPE AND HIGHER PWATS. THE SHEAR IS NOT OVERLY IMPRESSIVE
BUT THERE IS MODEST MID-LEVEL LAPSE RATES OF 7-8 C/KM WHICH COULD
SUSTAIN UPDRAFTS IN CONJUNCTION WITH 20KTS OF SPEED SHEER SFC -
3KM AGL. IN SHORT, WIDESPREAD SHOWERS AND STORMS ARE EXPECTED WITH
THIS VORT MAX, AND I WOULD NOT BE SURPRISED TO SEE A STRONGER
STORM IN CARTER CO. MT THIS EVENING.
MONDAY INTO TUESDAY THERE IS DECENT AGREEMENT AMONGST MODELS THAT
A SHORTWAVE WILL PUSH THROUGH NE MT WITH A TRAILING COLD FRONT
THROUGH OUR AREA. WHILE THIS FRONT WILL NOT BRING IN ANY
MEANINGFUL COOLDOWN THIS WILL BE ANOTHER SHOT AT PRECIPITATION FOR
MOST OF THE CWA. THE TIMING VARIES BETWEEN MONDAY EVENING AND
TUESDAY MIDDAY FOR WHEN EXACTLY THE FRONT WILL MOVE THROUGH AS
WELL AS EXACT PRECIP AMOUNTS. THE NBM 10-90TH SHOWS A SPREAD OF
0-0.4 FOR MOST OF THE CWA AND DUE TO THE SHOWERY NATURE OF THE
PRECIPITATION, IT WILL LIKELY BE YET ANOTHER TALE OF THOSE WHO SEE
A LOT OF PRECIP AND THOSE WHO SEE NONE.
GOOD NEWS FOR THOSE WHO LOVE SUMMER, ENSEMBLES ARE CONSISTENTLY
SHOWING A RIGE BUILDING BACK INTO THE INTERMOUNTAIN REGION
MIDWEEK. THESE SAME ENSEMBLES DO DISAGREE ON TEMPERATURE VALUES
THOUGH. SOME SHOW HIGHS SLIGHTLY ABOVE AVERAGE FOR THE MIDDLE TO
LATE PART OF NEXT WEEK WHILE OTHERS SHOW US FLIRTING WITH TRIPLE
DIGITS AGAIN NEXT WEEKEND. THIS WILL LIKELY DEPEND ON THE
DIRECTION OF OUR SURFACE WINDS AND WHETHER OR NOT THIS RIDGE
INDUCES ANY MONSOONAL MOISTURE / STORMS. WMR
AVIATION
ISOLATED SHOWERS AND A THUNDERSTORM OR TWO ARE POSSIBLE (10 TO
40% CHANCE) THROUGH 15Z THIS MORNING, MAINLY EAST OF KBIL. HEAVY
RAIN MAY CAUSE MVFR CONDITIONS. FOG WILL BE POSSIBLE AT ALL TAF
SITES THIS MORNING FROM 09Z THROUGH 15Z. DID NOT INCLUDE FOG IN
THE TAFS THOUGH DUE TO LOW CONFIDENCE. THE BEST POTENTIAL FOR FOG
DEVELOPMENT WILL BE LOCATIONS EAST OF BILLINGS. ADDITIONAL SHOWERS
AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON/EVENING, MAINLY FOR
TERMINALS NEAR THE MOUNTAINS AND FOOTHILLS (INCLUDING KLVM, KRED,
AND KSHR). THE PRIMARY IMPACTS WITH ANY STORMS ARE HEAVY RAIN,
LIGHTNING, AND ERRATIC WIND GUSTS. MATOS
PRELIMINARY POINT TEMP/POPS
TDY MON TUE WED THU FRI SAT
-------------------------------------------------------
BIL 085 059/083 059/082 057/086 060/090 061/090 063/090
0/U 31/E 44/T 40/U 10/U 11/B 22/W
LVM 084 046/084 049/082 046/084 049/088 052/089 054/088
2/T 51/B 54/T 40/U 11/U 12/W 34/T
HDN 086 054/085 055/084 052/088 054/092 056/092 059/093
0/U 21/E 44/T 30/U 10/U 01/B 22/W
MLS 084 058/083 057/081 055/087 059/091 059/090 062/091
2/T 20/B 72/T 40/U 10/U 01/U 21/B
4BQ 084 059/085 059/082 057/086 059/090 060/090 063/091
2/T 22/B 55/T 42/T 10/U 01/U 11/B
BHK 083 052/083 051/080 050/085 054/090 055/088 056/089
2/T 32/B 72/T 22/T 10/U 00/U 21/U
SHR 080 051/081 052/079 050/082 052/088 054/090 057/090
2/T 22/B 46/T 33/T 10/U 01/U 12/T
BYZ WATCHES/WARNINGS/ADVISORIES
MT...NONE.
WY...NONE.
WEATHER.GOV/BILLINGS
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